Keeping track of entity owners

[Briggybros]

Hello, I'm trying to make a mod which you own an entity, but you can only own one entity. I have created a list object which uses the Players EntityID as the index and then the instance of EntityHorse as the listed object. I have this code to decide whether to teleport the horse or spawn one;

    public ItemStack onItemRightClick(ItemStack par1ItemStack, World par2World, EntityPlayer par3EntityPlayer)
    {
        if (!par2World.isRemote)
        {
        	int playerID = par3EntityPlayer.entityId;
           	if(BattleFoxCox.horses.get(playerID) != null) // line 39
           	{
                EntityHorse entityHorse = new EntityHorse(par2World);
            	entityHorse.setLocationAndAngles(par3EntityPlayer.posX, par3EntityPlayer.posY, par3EntityPlayer.posZ, par2World.rand.nextFloat() * 360.0F, 0.0F);
               	par2World.spawnEntityInWorld(entityHorse);
               	entityHorse.setOwner(par3EntityPlayer.username);
                BattleFoxCox.horses.set(par3EntityPlayer.entityId, entityHorse);
            }
            else
            {
            	EntityHorse entityHorse = BattleFoxCox.horses.get(playerID);
            	entityHorse.setLocationAndAngles(par3EntityPlayer.posX, par3EntityPlayer.posY, par3EntityPlayer.posZ, par2World.rand.nextFloat() * 360.0F, 0.0F);
            }
            
        }

        return par1ItemStack;
    }

 

I know it's probably horribly wrong but I've never done anything with entities before. When I try to use the item this error is thrown.

2012-09-26 18:27:36 [sEVERE] [ForgeModLoader] A critical server error occured handling a packet, kicking net.minecraft.src.NetServerHandler@11038df
java.lang.NullPointerException
at uk.co.toomuchminecraft.battlefoxcox.ItemHorseShoe.onItemRightClick(ItemHorseShoe.java:39)
at net.minecraft.src.ItemStack.useItemRightClick(ItemStack.java:139)
at net.minecraft.src.ItemInWorldManager.tryUseItem(ItemInWorldManager.java:306)
at net.minecraft.src.NetServerHandler.handlePlace(NetServerHandler.java:478)
at net.minecraft.src.Packet15Place.processPacket(Packet15Place.java:78)
at net.minecraft.src.MemoryConnection.processReadPackets(MemoryConnection.java:75)
at net.minecraft.src.NetServerHandler.networkTick(NetServerHandler.java:72)
at net.minecraft.src.NetworkListenThread.networkTick(NetworkListenThread.java:55)
at net.minecraft.src.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:111)
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:630)
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:547)
at net.minecraft.src.IntegratedServer.tick(IntegratedServer.java:105)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:453)
at net.minecraft.src.ThreadServerApplication.run(ThreadServerApplication.java:17)

[DarkGuardsman]

get your entity to save the owner's user name rather than EntityID. Then use World.getPlayerByName or something close to that to get the EntityPlayer instance.

[Briggybros]

My entity does save the owner's name. In that case how would I get the horse which has that player as its owner? The data which the horse currently saves is the owners username and the owners EntityPlayer instance. How could I get the instance of the Horse which has the owner as the user of the tool without editing base classes?

[LexManos]

Keep a record of your tamed horses.

[Briggybros]

I have done that, and that's what produced the error

 

EDIT: Found a way to do it, I'll reply after testing

 

EDIT: Now have the method;

    public ItemStack onItemRightClick(ItemStack par1ItemStack, World par2World, EntityPlayer par3EntityPlayer)
    {
        if (!par2World.isRemote)
        {
        	for(int x = 0; x < BattleFoxCox.horses.size(); x++)
        	{
        		EntityHorse horse = BattleFoxCox.horses.get(x);
        		if(horse.getOwnerName().equalsIgnoreCase(par3EntityPlayer.username))
        		{
        			horse.setLocationAndAngles(par3EntityPlayer.posX, par3EntityPlayer.posY, par3EntityPlayer.posZ, par2World.rand.nextFloat() * 360.0F, 0.0F);
        			break;
        		}
        		if(x == BattleFoxCox.horses.size())
        		{
        			EntityHorse entityHorse = new EntityHorse(par2World);
                	entityHorse.setLocationAndAngles(par3EntityPlayer.posX, par3EntityPlayer.posY, par3EntityPlayer.posZ, par2World.rand.nextFloat() * 360.0F, 0.0F);
                   	par2World.spawnEntityInWorld(entityHorse);
                   	entityHorse.setOwner(par3EntityPlayer.username);
                    BattleFoxCox.horses.add(entityHorse);
        		}
        	}
            
        }

        return par1ItemStack;
    }

not tested, I'll review it tomorrow and then test, too late now.

[Briggybros]

Now I have this method;

	public void grantHorse(EntityPlayer par1EntityPlayer, World par2World)
{
	EntityHorse entityHorse = new EntityHorse(par2World);
    	entityHorse.setLocationAndAngles(par1EntityPlayer.posX, par1EntityPlayer.posY, par1EntityPlayer.posZ, par2World.rand.nextFloat() * 360.0F, 0.0F);
       	par2World.spawnEntityInWorld(entityHorse);
       	entityHorse.setOwner(par1EntityPlayer.username);
       	BattleFoxCox.addHorseToList(entityHorse);
}

public void moveHorse(EntityPlayer par1EntityPlayer, EntityHorse par2EntityHorse, World par3World)
{
	par2EntityHorse.setLocationAndAngles(par1EntityPlayer.posX, par1EntityPlayer.posY, par1EntityPlayer.posZ, par3World.rand.nextFloat() * 360.0F, 0.0F);
}

    /**
     * Called whenever this item is equipped and the right mouse button is pressed. Args: itemStack, world, entityPlayer
     */
    public ItemStack onItemRightClick(ItemStack par1ItemStack, World par2World, EntityPlayer par3EntityPlayer)
    {
        if (!par2World.isRemote)
        {
        	if(BattleFoxCox.horses != null)
        	{
        		for(EntityHorse horse: BattleFoxCox.horses)
        		{
        			if(horse.getOwnerName().equalsIgnoreCase(par3EntityPlayer.username))
        			{
        				this.moveHorse(par3EntityPlayer, horse, par2World);
        				break;
        			}
        		}
        	}
        	else
        	{
        		this.grantHorse(par3EntityPlayer, par2World);
        	}
            
        }

        return par1ItemStack;
    }

 

How would I get it so that it triggers the moveHorse if the for each loop is not broken?